Compressed foliated wood



' June 6, 1944. M. F. cRoUl-:T

v COMPRESSED FOLIATED WOOD Wmv Patented `lune 6, 1944V UNITED STATES PATENT OFFICE commessa rouArEn woon Marcel Francois Crouet, Beauchamp, France;

vested in the Allen Property Custodian Application May 19, 1942, Serial N0. '443,629

In France October 30, 1941 1 Claim.

l cal and mechanical resistances can be determined according to the use for which the structure is produced, by the relative thicknesses of the layers in two sets, respectively, forming the structure, the'layers of one set being impregnated with a polymerisabl'e resin and the layers of the other set being unimpregnated.

Compressed woods are already known which are formed of thin sheets arranged above another and more particularly the following ones:

' l. A wood formed of thin sheets impregnated iinal product is intended.

with polymerisable resin in vacuo and under pressure or by any other means, this wood being com- I this large quantity of resin its mechanical rel sistanceis small.

2. rit; wood formed of non-impregnated sheets which are only coated with a polymerisable resin on each of their lfaces, this wood being compressed to form a block having a predetermined number oi' sheets. With thisvmethod of manufacture the coated races are always'in contact with another.

This wood possesses better mechanical resistance than the wood described under l, owing to the small quantity of-resln, but conversely the physical resistance is lower.

3. A compressed wood formed of thin sheets which have been preferably compressed and then coated with polymerisable resin on eachof their faces and glued together to 4form blocks having a predetermined number' of sheets. As regards the resistances which are obtained this wood is similar to that which'has been described under 2.

Contrary to this the present invention relates relative thicknesses of the impregnated. and 'of Ithe natural sheets.4

According to a form of embodiment each impregnated sheet is inserted between two sheets of natural wood, the said impregnated sheet acting` as a gluing agent owing to the resin which it contains.

The sheets can be of variable thicknesses and of different species of wood.

The sheets can be arranged parallelly or perpendicularly or in a predetermined angle with one another according to the use for which the The-compression of the sheets forming the homogeneous blocks in order to obtain the said blocks is effected in a press with heating plates `or moulds.

The pressure andthe temperature which are used vary according to the kind of product to be obtained and to the synthetic resin which is used.

The thin veneering sheets which are used can be obtained by peeling, cutting or sawing.

Compressed foliated woods according to the invention are shown by way of example in the appended drawing in which Figures 1, 2 and 3 are three sectional views of three-blocks of the said foliated woods.

kFigure 1 shows a compressed foliated wood formed of impregnated sheets IV ofsubstantial thickness E and of natural sheets 2 of small thickness e. The sheets I are impregnated with syn. thetic resin.

This compressed foliated wood possesses a good physical resistance.A o f v Figure 2 shows a block oi thick natural sheets 2'- with very thin sheets i* impregnated with resin,v this wood possesses good mechanical resistance. I

It is desirable to use, for this composition, relatively incompressible woods such as acacia or' hombeam for the natural sheets and sof-t very. compressible woods for the impregnated sheets.

Figure 3 shows a block formed of impregnated sheets lh and of natural sheets 2b having the same thickness; this wood possesses nicely balanced physical -and mechanical resistances.

I claim: v v

A compressed plywood ,structure comprising a1- temate impregnated and unimpregnated wood plies, the impregnated plies containing throughout their structure a polymerisable resin, and having a thickness several times greater than that of the unimpregnated plies, thereby increasing the physical resistance and decreasing the mechanical resistance ofthe structure.

MARCEL FRANcorsfcRduEn 

